Project Summary/Abstract This proposal seeks five years of additional funding to examine in depth the structural and functional neural, behavioral, and cognitive correlates of three fundamental dimensions of the time course of emotion: a) the rapidity with which an individual recovers from negative affect, b) the duration with which positive affect persists, and c) the change (e.g. habituation) in affective responses across repeated stimuli presentations. These three important features of affective chronometry have received very little attention, and their neural bases and psychological correlates are not well understood. The proposed research will be carried out in a set of six inter-related aims. The measures described for each will be obtained in the same 350 participants between the ages of 25-45 years, and include facial EMG measures of corrugator and zygomatic activity and fMRI activity recorded in response to affective picture presentations. From these measures, metrics of individual differences in recovery from negative affect, persistence of positive affect, and change across repeated stimulations will be derived. We will investigate the impact of these affective chronometric measures on subsequent memory for the stimuli. The Trier Social Stress Test will also be used to assess affective chronometry through the lens of stress reactivity, quantified via the rise and fall of stress hormones in saliva and perceived stress. Outside the laboratory, we will obtain day reconstructions and ecological momentary assessment, or experience sampling, in the context of a simple probabilistic reward and punishment task that involves winning or losing money. From these measures, we can examine the temporal dynamics of affective responses in the field. All participants will complete questionnaires and undergo clinical diagnostic interviews to assess for mental health symptomatology and trait affect, as well as a cognitive battery assessing executive function and attentional flexibility. Collectively, this incredibly rich dataset will allow us to systematically characterize the import of these affective chronometric measures for varied domains including emotional memory, stress reactivity, mental health, cognition, daily emotional experiences, and reward responsivity, while elucidating the critical functional and structural brain substrates underlying these relationships. Overall, we predict that faster recovery from negative affect, greater persistence of positive affect, and less response change across repeated occurrences of positive incentives will be adaptive, associated with well-being and fewer depressive symptoms, and instantiated in circuits that involve both lateral and medial prefrontal- amygdala connectivity and lateral and medial prefrontal-ventral striatal connectivity. Support for these predictions would provide strong evidence that affective chronometry is a critical factor to include in the RDoC negative and positive valence system domains.